1. Field of the Invention
This invention relates to doors for controlling the discharge flow of materials from a railway car hopper or the like.
2. Prior Art Related to the Disclosure
Heretofore, discharge doors for materials contained in railway hopper cars and the like have employed two types of doors for controlled release of the car contents. One type of discharge door currently in use is a slidable flat plate which is operated by a rack and pinion operating mechanism. Fine particles collect and are compacted along the top surface of discharge doors of this type. In addition, the weight of the material on the gate increases the frictional forces between the slidable plate and the plate guides which forces must be overcome by the rack and pinion operating mechanism.
A second type of discharge gate uses a hinged discharge door. A typical mechanism for operating a railway hopper car door is disclosed in U.S. Pat. No. 825,581, which shows a flat door tilted open by a plurality of pivotable crank arms to which are mounted pins which engage slots formed on a door assembly. U.S. Pat. No. 902,749 shows a rather complicated latch and operating mechanism for a railway car door which includes a small-diametered roller mounted at the end of a door-lifting arm, which roller engages a wearing shoe mounted to the underside of a flat door.
The various types of prior door and operating mechanisms, such as the two types mentioned above, are rather complicated in design and expensive to fabricate and maintain.